Cheap Alternative to DT Swiss Adaptor

Great forum! long time lurker, but finally decided to post because it seems there havent been many questions abt this, and sorry if i was not able to search properly.

im looking to put some 6-bolt 160mm rotors on my bike. the trouble is tht the hubs on my bike have centrelock mechanism.

I came across DT swiss's centrelock to 6bolt adapter, but its 36 bucks each! it seems like a high price. i was wondering if there are any cheap alternatives available which i can look at, or is the price standard and i should go ahead with these? thanks a lot.

The alligator ones are only for $10- are they as durable as the expensive ones? I understand that it does not come with a lockring, but i have spares. If the alligator ones work, I might just jump on them.

And crisillo, can you tell me if there are any websites retailing the shimano adaptors?